In order to prolong service time of a mobile product, there is proposed a low frequency drive technique at present. Such low frequency drive technique reduces power consumption of the mobile product which are displaying by reducing refresh frequency of the display device. However, such technique would prolong the time of one frame. In actual application, due to existence of leakage current, pixel voltage in a liquid crystal display device would gradually drop with time. This would lead to change of luminance. For example, for a display driving device in a normally black mode, as a pixel voltage within one frame declines gradually, it would cause display luminance decrease gradually, thereby resulting in picture flicker. Such a phenomenon is particularly evident in the liquid crystal display device that adopts the low frequency drive technique.